1. Field of the Invention
The present invention relates to a plasma processing apparatus and a plasma processing method for processing a substrate with plasma generated in a process vessel.
2. Description of the Related Art
In manufacturing processes of, for example, a semiconductor device, a liquid crystal display device, and the like, plasma processing by a plasma processing apparatus is widely used for subjecting a semiconductor wafer to processing such as etching and film formation Such a plasma processing apparatus includes, in a process vessel, upper and lower electrodes facing each other, and a radio-frequency power is supplied to the lower electrode on which, for example, a substrate is placed to generate plasma between the lower electrode and the upper electrode, thereby processing the substrate.
In this plasma processing apparatus, conventionally, in order to enhance anisotropy of etching and increase etching rate and deposition rate for increased product yields, various process gases have been used and pressure and temperature of the process gases have been adjusted. Further, the present applicant has disclosed a method to keep high in-plane uniformity of plasma processing by varying impedance on an electrode side of the plasma generated in the process vessel to frequency of a radio-frequency power source (see, for example, Japanese Patent Application Laid-open No. 2004-96066).